To avoid damage to an electronic device, a power management integrated circuit (PMIC) is used to regulate an operating voltage and to monitor an operating current supplied to the electronic device. By monitoring the operating current, both the PMIC and the electronic device is able to be protected from damage resulting from sudden increases in operating currents, such as those associated with an open or short circuit. Additionally, in PMICs which operate using multiple phases to manage power supply, accurate monitoring of the operating current increases efficiency by activating only those phases necessary to supply a requisite operating current.
In a conventional arrangement, a voltage drop across a single resistor is measured to determine the operating current. However, as the temperature of the resistor changes due to heating during normal operation, the resistance of the resistor changes thereby affecting the measurement of the actual operating current. The change in resistance results in a change in the voltage drop, which in turn changes the measurement of the actual operating current.